FOR weeks, pundits and editorialists have been offering George W. Bush all sorts of advice about how to get his supposedly troubled presidency back on track.

On one level, it’s an exercise in political farce, since these “advisers” tend to be anti-Republican and anti-conservative, and would like nothing more than for his presidency to founder.

Even more comical is the notion that a presidency that seemed illegitimate to many millions of Americans by the nature of its Supreme Court-midwived birth is now being treated as though it’s teetering on the verge of a political abyss because Bush’s approval rating is hovering around 50 percent.

In fact, Bush’s ideological opponents are engaged in a clever game that you might call “defining political illegitimacy down.”

His declining poll numbers are not merely snapshots of a presidency and a nation in the midst of economic uncertainty. Oh, no, say the pundits: They are reports from the front lines of national public opinion, which has already made up its mind that Bush favors the rich, hates the environment and wants to line the pockets of evil oil companies.

Sound familiar? It should, because it’s the Gore-campaign line on Bush updated to the summer of 2001. The pro-Gore pundits are, in effect, declaring Bush’s presidency illegitimate because a) one very liberal Republican senator from Vermont decided to switch parties and b) Bush’s poll numbers aren’t as high as Bill Clinton’s were during the two-year period when the U.S. economy was the strongest the world had ever seen.

But there’s something more pernicious going on here. For the effort to delegitimize Bush is, more profoundly, an effort to delegitimize conservative ideas by declaring them “beyond the mainstream” – a form of political combat that stifles debate, poisons serious discourse and does violence to the truth.

In a mind-boggling Washington Post op-ed on June 19, Edward Lazarus advanced the startling argument that the “best of Bush’s ideological nominees” should be rejected by the Senate because their effort to rule based on what the Constitution actually says is “irremediably flawed.”

After spending 20 years demanding that right-wingers impose no litmus tests on judicial nominees, liberals are now making conservatism itself the ultimate litmus test.

The delegitimacy game is a pretty audacious effort, considering how evenly divided the nation’s electorate is. The same polls that have been used to create the image of a presidency in crisis can be read in another way entirely. Bush, it seems, has the support of all those who voted for him in November. He’s doing a lot better at holding his own voting base than did Bill Clinton in 1993 – and he seems on track to avoid any major calamity in the midterm elections in 2002.

That’s an important political accomplishment, one it’s easy to overlook and underestimate. Bush was dealt a difficult political hand in November. He’ s played it far more deftly than anyone imagined.

What threatens him is not his conservatism, his views on the environment or anything like that. Those are what has solidified his base of support among conservative and right-leaning voters – voters who remain, as ever, invisible to the advice-givers counseling the president to abandon his principles and ideals.

No, Bush is threatened by the economy, pure and simple. And how that shakes out, nobody knows.